Mahmood al-Zarooni has stunned the British racing establishment by launching an appeal against the eight-year ban he was given after he admitted doping horses with anabolic steroids. The appeal, which is confined to the length of the ban and is not made against the conviction itself, came as a surprise to many, despite a Facebook account in Zarooni's name suggesting last week that he would take such action.

No date has yet been set for the appeal hearing, in contrast to the haste with which the matter was originally dealt with. The British Horseracing Authority's disciplinary panel heard the case and issued its verdict just three days after charges were issued against Zarooni last month, but a spokesman for the BHA said on Tuesday it was not yet clear how quickly an appeal panel could be convened.

Zarooni appears to have indulged in a certain amount of brinksmanship in submitting the necessary paperwork, which reached the BHA mid-afternoon on Tuesday. The deadline for making an appeal was widely reported as being 5pm on Monday and it only emerged on Tuesday morning that the deadline had been held over 24 hours because of the Bank Holiday.

The development was signalled last week, when a posting appeared on a Facebook account in Zarooni's name, saying: "I have been advised to appeal the case, what are your opinions?" However, the authenticity of the account has been widely doubted.

The BHA has not yet been advised as to the basis for Zarooni's appeal and he is not obliged to offer specifics until the hearing itself, beyond stating his intention to argue for a more lenient penalty. He had no representation at the first hearing, despite early indications that he had hired the solicitor Gavin Bacon, but he has engaged William Clegg QC to represent him this time.

Clegg's biography states that he has "appeared before various professional regulatory and disciplinary bodies" and that he has worked with lawyers in Dubai, Zarooni's home. Zarooni's solicitors are now the London-based firm Russell Cooke, where his case is being handled by two partners including Matt Bosworth, whose online profile describes a background in sports law and that he advises Newcastle United FC on media coverage of the club.

The BHA's panel described Zarooni as acting alone when applying steroids to a total of 15 horses and reported that he instructed junior members of staff to inject horses with the contents of unmarked syringes. Even so, the case has been profoundly embarrassing to his former employers at Godolphin, the racing operation of Dubai's ruler, Sheikh Mohammed, who refused to discuss it in a live interview on Channel 4 at the weekend.

On Tuesday, that policy was followed by Godolphin's spokesman, Simon Crisford, who said: "This is a matter between Mahmood al-Zarooni and the BHA. It has nothing whatsoever to do with Godolphin."

The BHA confined itself to a terse statement confirming the appeal, which went on to say that all horses formerly trained in Newmarket by Zarooni have now been tested and the results will be published "in due course". Privately, there is some dismay amongst officials that the matter cannot yet be filed and forgotten, that it will undermine racing coverage in the buildup to the Derby on 1 June, just as it all but wiped out advance coverage of last Saturday's 2,000 Guineas.

Meanwhile, in a sign that Sheikh Mohammed is not yet ready to distance himself from racing, it was revealed that he has bought the exciting Irish colt Fort Knox, who is trained by Tommy Carmody and will now be aimed at the Irish 2,000 Guineas a fortnight on Saturday. Johnny Murtagh, who owns Carmody's yard, said the horse would race in the Sheikh's own maroon silks rather than the royal blue of Godolphin.